The proposed pre-doctoral training program in the field of medical physics (Research Training in Medical Physics) represents a competitive renewal for Years 26 to 30 of this successful and long-standing graduate program. Training toward the Ph.D. degree is conducted through the Graduate Program in Medical Physics, which functions within the Committee on Medical Physics at The University of Chicago. This program has been training students since the mid-1950s and is currently training 20 graduate student pre-doctoral trainees through the dedicated participation of 21 faculty trainers. The proposed program seeks funding for six pre-doctoral students per year. The Graduate Program in Medical Physics at The University of Chicago provides trainees with a complete curriculum of rigorous courses combined with mentored research in medical imaging and radiation therapy physics. Exposure to teaching opportunities and required courses in scientific ethics and the responsible conduct of research forms an essential element of the pre-doctoral training. The quality of the Graduate Program in Medical Physics has continued to evolve with improvements including (1) reorganization of the curricular requirements, (2) revision of the first-year research rotation requirement with the intent of having students commit to a lab for their thesis research after at most one full year (four academic quarters) in the Program, (3) creation of a required ethics course (Bioethics for Medical Physicists) tailored specifically to the domain-specific needs of medical physics trainees, (4) development of new courses (in health physics and molecular imaging) to cover aspects of the field of medical physics that have become part of national standards or have become of interest to students, and (5) initiation of a medical physics career development lecture series. The Program faculty continues to address the length of time to graduation. Medical physics is a broad field that requires competence in a wide range of topics from imaging physics to radiation therapy physics. Therefore, students in the Graduate Program in Medical Physics (relative to their colleagues in other disciplines) must take a greater number of courses to gain the core knowledge that spans the field. Nevertheless, the best interests of the students and the Program are served when students are presented with a clear process toward a timely graduation. Such a defined process to reduce the average time it takes students to graduate is useful for both students and faculty, since time to graduation necessarily depends on the cooperation of both groups: students need to demonstrate initiative and they must seek timely guidance from their faculty mentor, while faculty must make themselves available as mentors and they need to hold students accountable for advancing the research project. Improvements to the Program have been implemented and continue to be monitored in their effectiveness as measures to reduce the average time it takes students to graduate. The proposed training program is required to insure that medical physics researchers of tomorrow have proper and complete training prior to entry into academics or industry.